In the pursuit of a cleaner, more sustainable future, the world is witnessing a profound transformation in its energy landscape. With the expanding scale and utilization of renewable energy sources, the inherent intermittency and volatility of these new power generation methods have become increasingly evident, posing significant challenges to the stability and reliability of the global power grid. Consequently, advanced energy storage technologies have emerged as vital solutions to mitigate these challenges and enable the large-scale integration of renewable energy. This article delves into the ongoing multinational endeavors to accelerate the development and commercialization of novel storage technologies, highlighting key initiatives and innovations from the United Arab Emirates (UAE), Germany, and Japan.
Background and Importance of Advanced Energy Storage
As renewable energy sources like solar and wind gain prominence in the global energy mix, their inherent limitations of being weather-dependent and variable in output have underscored the need for effective energy storage solutions. Advanced energy storage technologies, encompassing novel lithium-ion batteries, compressed air energy storage (CAES), hydrogen (and ammonia) storage, and thermal (and cold) storage, among others, offer the potential to balance supply and demand, enhance grid resilience, and facilitate the transition to a clean, low-carbon energy system.
The United Arab Emirates: Pioneering Renewable Energy and Energy Storage
Thermal Energy Storage in Masdar City
The UAE, a major oil-producing nation, has embarked on an ambitious journey towards energy diversification and sustainability. Masdar City, a flagship project of the UAE’s renewable energy aspirations, recently announced the launch of a pioneering thermal energy storage (TES) project. This project leverages recycled aluminum and silicon-based phase change materials (PCM) to store energy in the form of heat, which can then be converted into electricity as needed. The system, which boasts exceptional performance, is poised to enhance the storage capacity of renewable energy sources and accelerate the country’s energy transition.
“2050 Energy Strategy” and “2050 Zero Emission Strategic Initiative”
Aligned with its broader vision, the UAE has set ambitious targets under its “2050 Energy Strategy” and “2050 Zero Emission Strategic Initiative.” By 2050, the country aims to increase the share of clean energy in its energy mix to 50% and achieve net-zero greenhouse gas emissions. To achieve these goals, the UAE is investing heavily in renewable energy projects, including the world’s largest solar thermal power plant, the Dubai Maktoum Solar Park, which utilizes advanced molten salt technology to ensure 24/7 electricity generation. Additionally, the UAE has embarked on green hydrogen projects, leveraging solar power to produce, store, and re-generate electricity from hydrogen, marking a significant milestone in the Middle East and North Africa region.
Germany
Germany has been actively promoting the widespread adoption of household energy storage systems. Across both urban and rural landscapes, solar photovoltaic panels adorn rooftops and facades, while in the basements of these buildings, refrigerator-sized devices – residential battery storage systems – reside. These systems, typically with a capacity below 10 kW, cater to the majority of a household’s electricity needs.
The integration of a complete household solar and storage system often entails an investment of tens of thousands of euros. Despite the substantial cost, many German families are willing to invest, aiming to mitigate the escalating electricity prices, contribute to environmental protection, and foster the adoption of green energy.
A report from the Technical University of Munich highlights the necessity of storing excess solar energy during peak production hours to compensate for fluctuations caused by weather conditions. Consequently, the number of patent applications for electrochemical storage technologies, predominantly lithium-ion battery-based, has surged in recent years.
Since the turn of the century, Germany’s renewable energy sector has flourished, with wind and solar power accounting for approximately 45% of total electricity generation, up from 3%. Germany boasts a global-leading average utilization rate of 97% for wind and solar energy, attributable to its robust energy storage network.
To incentivize the installation of storage devices, the German government has introduced a range of supportive measures, including granting loan subsidies of up to 30% and allowing tax deductions for the cost of storage equipment. Sonnen, Germany’s largest manufacturer of household energy storage systems, has developed a technology tailored for electric vehicle owners. Users of Sonnen’s charging stations can share their solar-generated electricity with others within a designated range, effectively forming a virtual, colossal energy storage system interconnected by power generation units, charging stations, and electric vehicle batteries. This system not only stabilizes the grid but also generates revenue for participants.
According to the latest data from the German Energy Storage Association, over 300,000 households in Germany have installed battery storage systems, with an average capacity of approximately 8.5 kW. By the end of 2020, nearly 70% of residential solar installations were equipped with battery storage facilities, totaling a capacity of approximately 2.3 GW.
Japan
Japan has focused its research and development efforts on hydrogen energy storage systems. In May last year, Shimizu Corporation, a Japanese construction firm, completed a zero-emission office building in Kanazawa City. This building integrates solar power generation and a hydrogen storage system, utilizing the company’s proprietary iron-titanium alloy hydrogen storage tanks. The office has achieved the Japanese government’s Zero Energy Building (ZEB) standard, signifying net-zero or negative annual primary energy consumption, achieving self-sufficiency in energy supply.
Shimizu’s researcher Hidesuke Shimoda emphasized the safety aspects of the iron-titanium hydrogen storage alloy, which underwent numerous tests to achieve its current flame-resistant composition. Notably, this alloy can absorb and store hydrogen at a density 1000 times its own volume, making a single alloy tank equivalent to 1000 atmospheric pressure hydrogen tanks of the same size. The iron-titanium alloy tanks are characterized by safety, economy, and high density, suitable for large-scale commercial applications.
The office’s rooftop is equipped with a 140 kW solar power installation, which produces hydrogen during periods of surplus electricity. The generated hydrogen is stored in the iron-titanium alloy tanks and utilized for power generation during times of insufficient solar output. The multiple hydrogen tanks installed underground cater to the building’s electricity demands.
In recent years, Japan’s hydrogen energy industry chain has expanded significantly, with hydrogen storage gradually transitioning from laboratory research to commercial application. Japan aims to achieve carbon neutrality by 2050, with renewable energy as the primary source of electricity. According to Japan’s Sixth Strategic Energy Plan, the share of renewable energy in electricity generation will increase from the current 19.8% to 36%–38% by 2030, with hydrogen storage system development being a top priority.
As reported by the Nikkan Kogyo Shimbun, a hydrogen-powered electricity storage system jointly developed by Ehnowa Corporation in Aichi Prefecture and the University of Tokyo has reduced its price to half that of similar products on the market. Professor Masakazu Sugiyama from the University of Tokyo, involved in the research, stated that converting solar power into hydrogen for low-cost, long-term storage, enabling “summer storage for winter use,” is entirely feasible and holds immense market potential upon commercialization.